The major aims of the proposed study are to assess specifically the tyrosinase activity and its electrophoretic patterns in the serum of patients with malignant diseases, to study the dissociation-association of the serum tyrosinase carrier and the enzyme and to explore a possible immunological aspect of the serum tyrosinase carrier. The proposed research is expected to provide a specific information concerning serum tyrosinase to be utilized for both diagnosis and immunotherapy of malignant disease or diseases. The specific determination of serum tyrosinase activity and fair demonstration of its electrophoretic pattern from an isolated serum fraction are already available. The dissociation-association of the serum tyrosinase carrier and the enzyme and the immunological aspect of the serum tyrosinase carrier can be initiated and approached by utilization of lipase digestion and many promising biochemical techniques. The undersigned agrees to accept responsibility for the scientific and technical conduct of the project and for provision of required progress reports if a grant is awarded as a result of this application.